The disclosed invention relates to video imaging systems, and is more particularly directed to a video signal processing technique for detection and correction of bad video channels.
AC coupled video imaging systems are utilized to provide video images of a scanned object scene. The scene being "looked at" is mechanically scanned (e.g., by a scan mirror) to provide optical radiation inputs to a plurality of detector elements, each of which is a channel that provides a detector output. The detector outputs are respectively AC coupled to amplifier stages which provide amplifier video signals. The amplifier video signals provided by the amplifier stages are utilized to produce a human observable display on an output transducer such as a CRT display or are further processed. As is well known, a video frame may include one or more fields where a plurality of fields are interlaced. On a video display, each video line of a field corresponds to the output of one detector element.
If one or more channels are bad (i.e., noisy or failed), the video signal is of reduced utility for further processing, and further results in a distorted video image. Typically, the bad channels are tolerated until sufficient problems occur to justify repair or maintenance procedures. Pursuant to such procedures, a channel adjacent a bad channel is hard wired to also provide the video signal for the bad channel. Alternately, the bad channels may be repaired or maintained as needed, which would result in unwanted down time.